Boiler



July 13, 1937. w. J. VOGE-L 2,086,786

BOILER Filed May 21, 1954 F" F 3" Z0\ 4 C if n 1,

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w W ATTORNEYJ I N VEN TOR.

Patented July 13, 1937 UNITED STATES PATENT OFFIQEV BOILER William J. Vogel, Montclair, N. J., assignor'to Combustion Engineering Co. Inc.,' New York, N. Y., a corporation of Delaware Application May 21,1934, Serial No. 726,620 1 '7 Claims. (01. 122 -3 03) This invention relates to improvements in boilers, and particularly boilers of the cross drum substantially horizontal tube type.

One ofthe primaryobjects. of my inventionis 5 the provisionofa boiler having a reserve water supply such as will be a protection against the development ofboiler hazards from causes such as feed pump trouble, sudden lossof load caused for example by turbinetrouble, or the suddenincrease or decrease in loads which occur particularly finrhigh capacity. installations The inven tioniis 2 especially useful in high capacity cross drum boiler installations having evaporating surfaces subject to radiant heat, which are .operated athigh ratings. 1

;.;The nature ofthe invention and the above and other objects will be best understood from the following. g

. :In boiler and furnace installations the present demandsiare for very highcapacities and operati'on at high. ratings. The advent of pulverized fu'elran'd better stokers has made it possible to increase boiler-ratings. sothat at the presenttime ratings-of. 400 toGOO percent are not uncommon.

a; Theemployment of radiantheat steam evaporating tubes in the furnaces has resulted in the provision of installations of very high capacity.

.gfIhe boilers employed in such installations, however, have not been materially changed, parr;; ticularly boilers of the cross drum type which have followed the conventional practice of using a single drum with the result that such boilers which were satisfactory heretofore, have limitations of such character that they will not take 4 care of the boiler problems of today, it being pointed out that the addition of steam evaporating tubes in the furnaces are a material factor in aggravatingboiler problems such as swelling or shrinkage of the water level due to sudden increased or decreased loads.

In the earlier low capacity installations, the problem of control of swelling was usually taken care; of by blowing the ,boiler down by hand when putting a boiler on the line. However, in increasing ratings, the element of time must be reckoned with, as it must also be if the load is lost sudeerily, due "for example, to turbine trouble. Losijrigthe load suddenly means a shrinking of the waterlevel perhaps to such an extent as to pass entirely out of the drum. On pulverized fuel installations the application of heat can be almost instantly discontinued, but in a stoker fired unit in which energy'is stored on the grate, this cannotbe done without dumping the grate, and

since this is not practical, sudden exposure of boiler parts to "excessive heat might cause considerable damage. I I

Another important point which must be considered is that of a continuous feed water supply which operators generally claim can be accomplished by changingfrom one pump to another within a minutes time. I-lowever, in a single drum unit of the ordinary construction, the supply.v of water in the drum is sufficient for only one minute or less, and therefore such units are 10 just about on the dead-line.fThe drum size has physical limitations which are Well known in this art.

In accordance with my invention, I overcome difliculties such as mentioned above by providing 15' reserve water supply for the protection of the unit by employing a, reserve water supply drum in a novel .manner, whereby I obtain definite assurance of having adequate water in the boiler parts under conditions such as above mentioned.

' Coming now-to'another aspect of my invention, I proposea novel formof gauge apparatus which while useful 'inaother boilers, is especially useful in boilers of my; improved type, the purpose of whichis to. give more accurate reading 25 than was heretofore possible with known gauge arrangements usually employing a single long gauge glass.

How-the foregoing-together with such other objects and advantages asmay hereinafter ap- 30 pear 'or are incident to my invention are realized is illustrated in preferred form in the accompanying drawing,.whereinr Fig. 1 isan elevational View illustrating a boiler embodying my. improvements associated with a combustion. chamber having steam evaporating tubes defining combustion space thereof; and

Figs. 2 and 3 are fragmentary elevationalviews illustrating modified gauge arrangements for the boiler; 1

In.Fig 1, I have. illustrated my improved boiler A associated with a' combustion chamber B of the type having radiant heat steam evaporating tubes defining the combustion space thereof, the combustion chamber being diagrammatically illus- 4 trated as having a row of upright steam evaporating tubes 4 at the rear wall, a similar row of tubes 5 at the front wall, and'a row of inclined tubes 6 extending across the bottom and connecting the lower-headers l of the rear wall 4 with the lower header f the front wall 5.

. The boiler A comprises in general an'upper steam'and water cross drum 9, an upper bank of'horizontally inclined boiler tubes II], a lower bank of similarly inclined boiler tubes H, down- 55 corner and upcomer headers l2 and 13 into which the tubes of the banks are connected, and a second or reserve water supply drum l4 located below the upper steam and water drum 9.

The drum M is connected to the drum 9 by means of a plurality of nipples l5 and to the downcomer headers 12 of the upper boiler bank by means of a plurality of nipples l6. These downcomer headers are also connected to the upper steam and water drum 9 by means of a plurality of nipples I'l bent well into the space above the. upper bank, and connected at their upper ends into the water space of the drum 9 and at their lower ends into the upper portions of the inner faces of the downcomer headers I2. A plurality of rows of delivery tubes l8 lead from the upper portion of the upcomer headers l3 of the upper bank H) to the steam and water drum 9, and. are

connected to deliver into the steam space thereof.

The steam evaporating tubes of the combustion chamber are supplied with water from the drum i l by means of downcomer tubes I9 leading therefrom to the lower header 1 of the rear wall 4. The tubular walls 4 and 5 are connected for delivery into the boiler by means of upcomer tubes 29 and El leading from the upper headers 22 and 23 thereof into the steam space of the upper steam and water drum 9. The boiler is suspended from overhead structure 24 as by means of straps 25.

By locating the auxiliary drum [4 immediately below the main steam and water drum 9, it is kept within the confines of the other boiler parts, and therefore within the usual column centres employed in such boilers, i. e., no additional space is required as would be required if the drum were placed to the rear of the drum 9, nor is the gas passage of the boiler blocked off or restricted as would be the case if the drum were placed to the front of and below the drum 9. Furthermore, my arrangement greatly simplifies the suspension of this drum and associatedparts, as well as the connections to the water walls.

In addition, by so locating the drum l4, water reserve is available in the high end of the upper bank of boiler tubes l0 ,due to the fact that the drum can be situated close to the downcomer headers l2, and it may be proportioned in size to suit the desired water reserve. Since the downcomer tubes [9 are connected into the drum N, there is definite assurance of water supply to the water walls of the combustion chamber.

The employment of the drum M as reserve capacity for drawdown is particularly advantageous where steam washers are used in the upper drum 9. These steam washers require considerable room, and since a lower level of water is carried in the upper steam and water drum when employing my invention, because of the fact that the drum 14 serves as a drawdown reserve which would otherwise have to be present in the bottom of the main steam and water drum, a greater surface of the steam washers will be exposed with the result that they will be much more effective than heretofore.

My improved gauge apparatus referred to above comprises a plurality of relatively short gauge glasses arranged at different levels and. having independent connection into the steam and water space of the boiler at different levels. In Fig, l, I have illustrated gauge glasses 2B and 21 for the drums 9 and M respectively, and a third gauge glass 28 located between the drums having upper connection into the lower portion of the drum 9 and lower connection into the upper portion of the drum l4 whereby an indication of the level in the drums as well as an indication of the water level as it passes between the drums may be obtained.

In Fig, 2, I have shown an arrangement in which a bi-color gauge 29 is employed in the upper drum 9 and a bi-color gauge 30 in the lower drum i4, these gauges being of the well known type which show green when steam is present in the glass, and red when water is present. Thus, in this arrangement, a definite location of the water level is obtained by the color in the gauge glasses. In the modification of Fig. 3, an alternate arrangement of bi-color gauges is illustrated in which the gauge 3! located between the two drums has upper connection into the steam space of the upper drum and lower connection into the upper portion of' the reserve drum, and in which the gauge 32 located at the level of the lower drum is similarly connected into the upper drum 9,

but has connection into the lower portion of the drum l4.

By thus providing a plurality of gauge glasses arranged serially at different levels, the error in indicated level is reduced as will be, seen from the following: The use of a plurality of relatively short gauge glasses connected individually as above mentioned is advantageous over a single long glass in that the level of the water in the glass will be nearer to the true level in the drum, this being so because, of the difierence in densities between the solid water in the gauge glass and the lighter steam-water mixture inthe drum. The greater the distance between the respective levels and the bottom connections, the greater the difference in levels of thetwo legs of the U-tube, i. e., the solid one in the gauge glass and the less dense one in the boiler drum. Thus, if a single long gauge glass were employed in Fig. 1 with. upper connection into the upper portion or steam space of the drum 9 and with lower connection into the lower portion of the drum #4, the error in the in dicated level would be much greater than-with my novel arrangement of a plurality of short glasses.

I claim:

1. In a high capacity steam generating installation, the combination of a boiler having an upper cross drum, horizontally inclined boiler tubes and downcomerand upcomer headers into which said tubes are connected, a reserve water supply drum, nipples connecting said supply drum to said cross drum, nipples connecting said supply drum to said downcomer headers, a combustion chamber below said boiler, steam evapcrating tubes. defining 'walls of said chamber, downcomer means leading from said reserve water supply drum to said steam evaporating tubes, and upcomer .means leading from said steam evaporating tubes to said boiler.

2. In a high capacity steam generating installation, the combination of a boiler having an upper cross drum, horizontally inclined boiler tubes and-downcomer and upcomer headers into which said tubes are connected, a reserve water supply drum, nipples connecting said supply drum to said cross drum, nipples connecting said supply drum to said downcomer headers, a com bustion chamber below said boiler, steam evaporating tubes defining walls of said chamber, downcomer means leading from said reserve water supply drum to said steam evaporating tubes, and upcomer means leading from said steam evaporating tubes to the steam space of said upper cross drum.

3. In a boiler having a main steam and water drum and a connected reserve water supply drum located therebelow, the combination of a plurality of relatively short gauge glasses connected into said drums, at least one of which has lower connection into' the reserve water supply drum and upper connection into the main steam and water drum.

4. In a boiler having a main steam and water drum and a connected reserve water supply drum located therebelow, the combination of a gauge glass having lower connection into the lower portion and upper connection into the upper portion of the main drum, a second gauge glass having lower connection into the lower portion and upper connection into the upper portion of the reserve drum, and a third'gauge glass having lower connection into the upper portion of the reserve drum and upper connection into the lower portion of the main drum.

5. In a boiler having a main steam and Water drum and a connected reserve water supply drum located therebelow, the combination of a gauge glass having lower connection into the lower portion of the reserve drum and upper connection into the upper portion of the main drum, and a second gauge glass having lower connection into the upper portion of the reserve drum, and upper connection into the upper portion of the main drum.

6. In a boiler having a main steam and water drum and a reserve water drum connected there- I to, the combination of a gauge glass having lower connection into the reserve water drum and upper connection into the main steam and water drum, and. a gauge glass having upper and lower connection into the main steam and water drum.

7. In a high capacity steam generating installation, the combination of a boiler having a steam and water drum, a reserve water supply drum located entirely beneath and connected to said steam and water drum, a combustion chamber associated with said boiler, upright steam evaporating tubes defining 'a wall of said combustion chamber, downcomer means connecting said reserve drum to said steam evaporating tubes, and upcomer means connecting said tubes to the boiler.

WILLIAM J. VOGELV 

